黄芪多糖影响糖尿病大鼠心肌氧化应激损伤的分子机制

Molecular mechanism of astragalus polysaccharide on myocardial oxidative stress damage in diabetic rats

目的:探讨黄芪多糖通过调节还原型烟酰胺腺嘌呤二核苷酸磷酸(NADPH)氧化酶p22phox和p47phox亚基表达影响糖尿病大鼠心肌氧化应激损伤的分子机制。方法:腹腔注射链脲佐菌素构建糖尿病大鼠模型,48只SD大鼠分为对照组、糖尿病组、黄芪多糖小剂量(200mg/kg)干预组及黄芪多糖大剂量(700mg/kg)干预组,12周后称重并计算心体比(H/B)和左室重量指数(LVMI),应用流式细胞仪检测心肌组织中活性氧(ROS)的表达,生化法检测血清超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-px)活性和心肌细胞GSH含量,Western blot及Real time PCR检测心肌组织中P22Phox、p47phox、核因子κb(NF-κB)、连接蛋白(FN)、Ⅲ型胶原蛋白(ColⅢ)和p-Akt的蛋白及mRNA表达。结果:与对照组相比,糖尿病组H/B、LVMI、ROS水平、p22Phox、p47phox、NF-κB、FN、ColⅢ和p-Akt表达显著升高,SOD、GSH-px和心肌细胞中GSH含量显著降低;黄芪多糖干预后,大鼠心肌H/B、LVMI、ROS水平、p22Phox、p47phox、NF-κB、FN、ColⅢ和p-Akt表达显著低于糖尿病组,SOD、GSH-px和心肌细胞中GSH含量显著升高,且呈剂量依赖性。结论:黄芪多糖干预可减轻糖尿病大鼠心肌病变。

Objective：To investigate the effect and mechanism of astragalus polysaccharide on myocardial oxidative stress damage of diabetic rats through regulating the expression of NADPH oxidase p22Phox and p47Phox subunit. Method：Fourty-eight SD rats were randomized into four groups： control group, diabetes mellitus group, astragalus polysaccharide low dose group （200 mg/kg）, and astragalus polysaceharide high dose group （700 mg/ kg）. The ratio of heart weight to body weight （H/B） and the left vent ricle mass index （LVMI） was calculated; the ROS level in rats heart muscle cells was measured by flow cytometry; the activity of SOD and GSH-px, the expression of GSH in rats heart muscle cells was measured by biochemistry assasys; the protein and mRNA expression of p22Phox, p47phox, NF-κB, FN, ColⅢ and p-Akt were measured by western blot and real time PCR after 12 weeks. Result：Diabetes mellitus group showed significant increases in H/B, LVMI, ROS level, the expression of p22Phox, p47phox, NF-κB, FN, ColⅢ and p-Akt, and significant decreases in the activity of SOD and GSH-px, the expression of GSH than those in control group. Two astragalus polysaccharide treatment groups reduced the level of H/B, LVMI, ROS, the expression of p22Phox, p47phox, NF-κB, FN, CollH and p-Akt, and increased the activity of SOD and GSH-px, the expression of GSH; meanwhile, compared with the astragalus polysaccharide low dose group, the change of above parameters were more significant in the astragalus polysaccharide high dose group, with dose dependent. Conclusion：Astragalus polysaccharide inhibits diabetic cardiomyopathy of diabetic rats.